This descriptor expresses local color structure in an image
using an 8 x 8-structuring element. It counts the number of
times a particular color is contained within the structuring
element as the structuring element scans the image. Suppose
$c_{0},c_{1},c_{2},\ldots c_{M-1} $ denote the M quantized colors. A color
structure histogram can then be denoted by $h(m)$,m=0,1,2,\ldots M-1 where the
value in each bin represents the number of structuring elements in the image containing one
or more pixels with color $c_{m}$. The HMMD color space is used
in this descriptor.